1. Field of the Invention
The present invention relates to a method for repeatedly using an image holding member in which an image is formed on the image holding member by using toner by an image forming apparatus such as a copying machine, a facsimile telegraph, a printer, etc., and the image holding member is reused by removing this toner from the image holding member.
2. Description of the Related Art
There are generally various kinds of known methods and apparatuses for regenerating an image holding member by removing toner from a sheet of paper as a recorded image holding member. For example, Japanese Patent Application Laying Open (KOKAI) No. 1-101576 shows a toner removing method using a solvent. In this removing method, toner is attached onto a sheet of paper and this paper sheet is dipped into a soluble solvent of toner resin. Then, a supersonic wave is vibrated in this paper sheet so that the toner dissolved into the solvent is separated from a paper face. Japanese Patent Application Laying Open (KOKAI) No. 4-300395 shows another toner removing method. In this removing method, toner is dissolved in a printed portion of a sheet of used paper by attaching a solvent to this printed portion using a dipping, spraying or coating method, etc. The dissolved toner is removed from the printed portion by a method using cleaning, air suction, absorbent contact, mechanical separation or electrostatic adsorption, etc.
In contrast to this, for example, Japanese Patent Application Laying Open (KOKAI) No. 2-255195 shows a toner removing method in which no solvent is used. In this removing method, thermally melted toner is attached onto a printed member by an electrophotographic system or a thermal transfer system. In this printed member, a mold-releasing agent is coated and attached onto a supporting member. This printed member is then overlapped with a toner separating member and is moved between a heating roller and a pressure roller. After this printed member is cooled, the toner separating member is separated from the printed member so that the toner is attached onto the toner separating member and is removed from the printed member. Japanese Patent Application Laying Open (KOKAI) No. 4-64472 shows an eraser having at least an endless sheet, a heating roller, a cooling roller, a pressing roller and a driving section for operating these members in association with each other. The endless sheet has thermally melted resin on a surface thereof. The heating and cooling rollers support and rotate this endless sheet. The pressing roller presses a sheet of erasable paper having a mold-released surface against thermally softened or melted resin. Japanese Patent Application Laying Open (KOKAI) No. 4-82983 shows a toner removing apparatus having two parallel rollers, a heater, a scraper and a separator. The two parallel rollers come in press contact with each other and are rotated such that a sheet of paper passes through a press contact portion of these rollers. The heater heats at least one of these two rollers. The scraper separates the paper sheet passing through the press contact portion from the parallel rollers. The separator removes toner attached onto the parallel rollers from these parallel rollers.
No solvent is used in the above removing method and apparatus. Each of the removing method and apparatus can be used to remove the toner from a recorded image holding member in which an image is recorded onto a sheet of normal paper having exposed paper fibers on a surface thereof. In this case, for example, the toner having thermally melted resin as a principal component is melted and attached onto the image holding member in a fixing process of the electrophotographic system. Therefore, the toner is strongly fixed to paper fibers on a surface of the image holding member. Accordingly, when the toner is removed from the image holding member, the paper fibers are removed from this surface together with the toner so that the paper sheet is damaged and a paper quality is reduced. In particular, when the image holding member on the above toner separating member, the endless sheet or each of the rollers is heated and pressurized to efficiently remove the toner from the image holding member, there is a case in which fixing force between the toner and the image holding member is conversely increased in accordance with various kinds of conditions. In this case, it is difficult to remove the toner from the image holding member.
Therefore, for example, inventors of this application proposed another toner removing method in Japanese patent application No. 4-255916. In this removing method, at least one kind of water or aqueous solution is selected from a group of water as an unstabilizing agent, an aqueous solution including a surfactant, an aqueous solution including a water-soluble polymer, and an aqueous solution including a surfactant and a water-soluble polymer. This selected water or aqueous solution is held in a recorded image holding member and is called a processing liquid in the following description. Toner is heated or pressurized and is adhered to a separating member so that the toner is separated from the image holding member. In this removing method, only the toner can be removed from the image holding member without relatively reducing a paper quality of the image holding member.
However, when the invention of this previous application is embodied, inventors of this application have found that the toner is not completely separated from the image holding member and is left on the image holding member in some kinds of the toner, and fibers on a surface of the image holding member are damaged at a separating time of the toner.